The toxicity of a strain of Spodoptera tilura nuclear polyhedrosis virus(SINPV)was tested.The 4th instar larvae of Spodoptera titura were used to carryout the bioassays.LC5e=2.014×104PIBs/eachlarva.The genomic DNA was digested with three restriction endonucleases BamHI,EcoRI and PstI,and 17,22 and 12 fragments were produced,respectively,The total genome size is 113kb.